There is a need for clinically-relevant imageable animal models of tumor blood flow, intravascular cancer-cell trafficking and extravasation, critical targets for current drug evaluation and development. Most models of tumor cell trafficking and blood flow are either based on subcutaneous transplantation of tumors or dorsal skin- fold window models. These models generally do not allow metastasis. There is also evidence that tumor vascularity may be organ-site specific and therefore orthotopic models would be very important. We have previously developed orthotopic metastatic models of cancer which express green fluorescent protein (GFP) (Nature Rev Cancer 5, 796-806, 2005). We have shown that these models enable high resolution whole-body imaging of tumor growth and metastasis and angiogenesis on internal organs (PNAS 97, 1206-11, 2000; 99, 3824-9, 2002). New developments in Phase I include the construction of dual-color cancer cells with GFP in the nucleus and RFP in the cytoplasm (Cancer Res 64, 4251-6, 2004; 65, 4246-52, 2005) that can enable imaging of tumor cell migration, nuclear-cytoplasmic dynamics, and extravasation in the live mouse. Nude mouse models with GFP-expressing blood vessels have also been developed in Phase I which can facilitate imaging of tumor blood flow (Cancer Res 64, 8651-6, 2004; 65, 5352-7, 2005). With these technologies developed during the Phase I grant, the Phase II grant will further develop these technologies in orthotopic models to evaluate inhibitors of tumor blood flow, intravascular tumor cell trafficking and extravasation. The specific aims include: (1) Use of transgenic nude mouse models with GFP blood vessels, orthotopically transplanted with RFP tumor cells for testing agents that target blood flow in the vessels of tumors and their metastasis; (2) Use of dual-color cancer cells with GFP in the nucleus and RFP in the cytoplasm orthotopically implanted in nude mice for in vivo testing of agents that target intravascular trafficking of tumor cells; (3) Use of dual-color cancer cells with GFP in the nucleus and RFP in the cytoplasm orthotopically implanted in nude mice for in vivo testing of agents that target extravasating tumor cells. These orthotopic models are unique in that they will enable visualization tumor blood flow, intravascular tumor-cell trafficking and extravasation at the nuclear-cytoplasmic dynamic level in clinically-relevant mouse models. The newly developed Olympus OV100 whole-mouse imaging system has optics for macro- and high-resolution subcellular imaging along with the models to screen an initial set of potential inhibitors that target these critical steps of metastasis. These models will be used commercially in Phase III to screen and evaluate large numbers of drugs and compound libraries. There is a need for clinically-relevant imageable animal models of tumor blood flow, intravascular cancer-cell trafficking and extravasation, critical targets for current drug evaluation and development. Most models of tumor cell trafficking and blood flow are either based on subcutaneous transplantation of tumors or dorsal skin- fold window models. These models generally do not allow metastasis. There is also evidence that tumor vascularity may be organ-site specific and therefore orthotopic models would be very important. With the technologies developed during the Phase I grant, this Phase II grant will further develop these technologies in orthotopic models to evaluate inhibitors of tumor blood flow, intravascular tumor cell trafficking and extravasation. [unreadable] [unreadable] [unreadable]